1. Chapter 2: Weathering and soil formation

2. Rocks and weathering
- Weathering – a process that breaks down rocks and other materials on Earth’s surface.
- Erosion – the action or movement of the weathered particles from one place to another by wind, water, ice or gravity.
See page 39 for examples!

3. Mechanical Weathering
When rock is PHYSICALLY broken down into smaller pieces – it is called mechanical weathering.
See pages for examples
Chalk demonstration

4. Chemical weathering
When a substance is broken down into smaller pieces through chemical changes – it is called chemical weathering.
Water – H2O
Oxygen – O2
Carbon Dioxide – CO2
Organisms
Acid Rain (H2SO4)

5. Rates of weathering
How fast or slow a rock weathers depends on the type of rock AND the climate.
See pages 44-45

6. How soil forms
Soil is loose, weathered material that helps plants grow.
Bedrock – solid layer of rock beneath the soil.
Page 49 – describes soil composition. Write the definition of soil composition in your notes using this page!!!

7. How soil forms
Soil formation is constantly occurring when bedrock is exposed to the weathering agents of nature and man.
See diagram on page 50 for details to help you with the GRP 2-2.

8. Living organisms in soil
Look at page 52-53…. See how all things can affect the soil and its composition.
What is humus? Humus is the material in soil that makes it fertile and usable for living things.